Medetomidine

Medetomidine is a veterinary sedative, similar to xylazine (tranq), that was first found in Philadelphia’s drug supply in May 2024. It is not an opioid, but is found in the dope (street opioids) supply. Although similar to xylazine, medetomidine is 100-200 times more potent and can cause longer-lasting sedation and low heart rates, as well as more severe withdrawal symptoms. Since the introduction of medetomidine, there has been a decrease in the presence of xylazine in Philadelphia’s drug supply, suggesting that medetomidine is quickly replacing xylazine in the dope supply.

In December 2024, PDPH released a health alert notification (HAN), and an accompanying community alert, describing the presence of medetomidine in the Philadelphia dope supply, which showed a large increase in the percentage of dope supply samples with medetomidine from May (29%) to November 2024 (87%). During this period, medetomidine was also found in overdose death data from the Philadelphia Medical Examiner’s Office (MEO) and was always found in combination with fentanyl.

Below are resources and information on medetomidine (chronological order, last updated 5/13/2025)

  • May 2024 Health Alert Network (HAN) notification

  • Community alert on the presence of medetomidine in Philadelphia’s drug supply

  • December 2024 HAN

  • Community alert on withdrawal symptoms associated with medetomidine use

  • Penn CAMP Medetomidine website

  • Penn CAMP Webinar

  • CDC MMWR Philadelphia

  • CDC MMWR Pittsburg

  • CDC MMWR Chicago

  • PDPH CHART (when available)

Symptoms and Overdose

The main effect of medetomidine is heavy sedation, but it can also cause low blood pressure and slow heart rate, dizziness, extreme tiredness, shortness of breath, nausea, blurred vision, and confusion.

There is no overdose reversal drug for medetomidine; however, it is always found in combination with fentanyl, so an overdose will most likely look like an opioid overdose. Since medetomidine causes deep sedation, the person will likely be unresponsive. This does not mean they are overdosing or that they should be given naloxone (Narcan) right away. The focus should be on breathing. If the person takes at least one breath every five seconds and is not pale, gray, or blue, they are not actively overdosing and do not require naloxone at the moment. If that changes, you should begin the overdose reversal steps, including giving naloxone. Since medetomidine’s effect is long-lasting sedation, even if the person begins breathing again after receiving naloxone, they may not be completely responsive. If possible, have a plan ready to monitor or transition the person.

Visit our training page [LINK] to learn how to recognize and reverse an opioid overdose.

Withdrawal

The effects of medetomidine differ from xylazine. This is clearly displayed in new emergency department (ED) syndromic data, which shows a rapid increase in ED visits for substance use withdrawal and a rapid decrease in ED visits for substance use related skin and soft tissue infections following the introduction of medetomidine. Read more about these trends in our recently published chart (LINK).

In December 2024, PDPH released a health alert notifying (HAN) providers of severe withdrawal symptoms requiring intensive care unit (ICU) level of care attributed to concurrent use of medetomidine and fentanyl. A supplemental community version was also released to inform the community of its effects. During withdrawal, medetomidine can cause racing heart rate, severe nausea and vomiting, excessive sweating, tremors, and confusion. Like xylazine, there is not a singular treatment strategy for medetomidine-involved withdrawal treatment. However, PDPH, as detailed in the HAN, has identified emerging treatment strategies and has provided recommendations for treating medetomidine-involved withdrawal in inpatient settings.

Additionally, in April 2025, the Penn Medicine Center for Addiction Medicine and Policy (CAMP), in partnership with PDPH, Jefferson Health, and Temple University, hosted a webinar discussion on new clinical findings and recommendations for medetomidine withdrawal. CAMP also published detailed clinical recommendations.

PDPH recommends a lower threshold in outpatient settings to refer patients experiencing withdrawal to a higher level of care if they are exhibiting severe symptoms.

Fast Facts

  • No. At the moment, we have only found medetomidine in combination with fentanyl, in dope samples.

  • Yes. Medetomidine test strips are now commercially available. These test strips allow individuals to test for the presence or absence of medetomidine in their substances. The Philadelphia Department of Public Health works with local community groups to distribute the tests strips. Find a community partner on the get supplies page. Medetomidine test strips work like fentanyl test strips- you just need to dip the strip in a mixture of a small amount of drug residue and water. Reading the results is the same as reading a fentanyl test strip, two lines mean that it is negative and medetomidine hasn't been detected, and one line means positive and that medetomidine was detected.

    Medetomidine test strips are a new tool. Information on the effects of the drug and recommendations for the use of these test strips can change. Continue to check this page for updated information.

    The Philadelphia Department of Public Health will continue to work with a forensic toxicology lab to test drug samples and identify emerging drugs, including medetomidine.

  • Unfortunately, medetomidine has been found in almost 90% of dope drug samples. However, if you're not sure, you can follow these steps.

    First, try to ask around and see how the drug is making other people feel before you buy or use it. Since medetomidine can cause a really heavy nod, try to use somewhere that you will be safe and won’t fall and hurt yourself. Finally, if you think there is medetomidine in your dope let others know - including someone at your local exchange program - so folks know to be careful.

  • No, other states including North Carolina, Ohio, and Illinois have identified medetomidine in their local supply. Read more about their cases in the Centers for Disease Control and Prevention (CDC)’s Morbidity and Mortality Weekly Report.

  • Not exactly. Medetomidine is not an opioid, so naloxone (NARCAN®) will not reverse a purely xylazine overdose. However, because medetomidine is always found in combination with opioids, including fentanyl, naloxone (NARCAN®) should still be administered whenever an opioid-involved overdose is suspected.

  • Research has not shown an association between medetomidine and skin wounds. Recent data from emergency department visits has shown that rates of substance use related skin and soft tissue infections (including wounds) fell to the lowest rate since Q1 2021 at the same time as the increase in medetomidine and the decrease in xylazine in the dope supply.

    If you are experiencing substance use related wounds, many organizations in the Kensington area offer wound care and supplies. View locations and hours of operation.

    Are you a medical provider looking for recommendations for treating substance use-associated wounds? Visit the resources for healthcare providers page for more information.

  • Yes. Withdrawal from medetomidine can cause racing heart, severe nausea and vomiting, excessive sweating, tremors, and confusion.

Printable Materials

This page is currently under development. Information regarding medetomidine, its effects, and treatment and harm reduction recommendations are still developing. Resources for community members, non-medical organizations, and healthcare providers will be available on this page as it becomes available. If you have any questions about information or material on this page, contact DPH.Opioid@phila.gov.